Like a number of other remote island communities, The Cook Islands have decided to get rid of expensive diesel power and go to 100% solar within the next few years. To do this they are constructing solar arrays backed up with small amounts of Li-ion battery storage which they believe will overcome the solar intermittency problem. Once again, however, the planners have failed to recognize the prohibitive amounts of battery storage that will be required, and their plans are doomed to fail as a result. The only approach that has any chance of succeeding is to minimize storage requirements by installing far more solar capacity than is needed to meet demand (“overgeneration”), but this approach has problems of its own. (Inset- Rarotonga, the largest and most populous of the Cook Islands).
The Cook Islands consist of 15 widely-separated islands, some inhabited, some not, located 3,000-4000 km northeast of New Zealand and divided into northern and southern groups (see map below). The Islands’ economic exclusion zone covers 1.8 million sq km but the islands themselves only 236 sq km:
According to the UN the population of the Cook Islands was 17,389 in 2017 and according to the World Bank its nominal GDP in 2016 was $US 311 million, giving it a per capita GDP of around $17,900, about the same as Slovakia. The unit of currency is the New Zealand dollar (The Cook Islands are self-governing but Cook Islanders have New Zealand citizenship). Tourism is the main industry.
The Cook Islands are effectively 100% grid-connected, with generation coming dominantly from 6.5MW of diesel plants (photo below). An unspecified amount of solar PV has also been installed, with the largest single installation being the 0.96 MW plant at the Rarotonga airport. Annual electricity consumption was 30.0 GWh in 2013 and peak load in 2011 was 4.83 MW. Because of the cost of imported diesel, however, electricity rates exceed those in either Denmark or South Australia.
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